Compound air brake



' Patntedept. 26, 1922 6 SHEETS-SHEET l.

W. G. CANION.

COMPouND AIR BRAKE.

, APPLICATION FILED JUNE 28, 1921.

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CCMPOUND AIR BRAKE.

APPucATmN man JUNEZS. 1921.

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YQ Si lu vanto@ qfviftmeoow W. G. CANION.

COMPOUND AIR BRAKE.

APPLICATION FILED JUNE 28, |921.

Patente Sept. 26, )1922 SHEETS-SHEET 3.

W. G. CANIUN.

COMPOUND AIR BRAKE.

APPLICATION FILED IuNE 28, 1921.

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WN Q I@ ANR Patented Sept. 26, 1922.

LASUyBQL W. G. CAMION, COMPOUND AIR BRAKE.

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W. G. CANION.

Patented Sept. 269 11922,

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s Si N` Si I k FH I l I l Q 5 I O Snom/Lto@ Patented Sept. 26, 1922- entran stares #Partnr carica. i.

WLLIAM Gt. CANTON, F BAJLTIMRE, MARYEAND, ASSIGNOJEJ T0 CNION AKR, BME COMPANY, OF BISBEE, ARIZONA, A CORPORATION' 0F ARIZGNA.

@@MPOUND MR BRAKE.

neled for abandoned application serial 11o. 346,881, lednne 28, 1914i. This application tiled nne 29,

1921. Serial 111e. 491,165.

To' aZZ whom t may concern.'

Be it known that I, WILLIAM Ur. CANION,

a citizen of the United States, residing at Baltimore, in the State of Maryland, have invented certain new and useful Improvements in Compound Air Brakes; and l do hereby declare the following to be a full, clear, and exact description of the invention', such as will enable others skilled in the art to which it appertains to make and usey the same. i

This invention is an improved compound air brake apparatus adapted to automatically take up the slack in the brake chain and to also automatically adjust a brake beam to compensate for the wear of the brake shoes and embodying a prime moving brake applying and slack adJusting piston arranged in and movable independently of the main brake applying piston which operates in the brake cylinder, and means for automatically controlling the operation of said pistons as hereinafter described and claimed.

This invention is an improvement Von the compound' air brake apparatuses described and claimed in my co-pending application for Letters-Patent of the United States, filed Sept. 25, 1913, Serial No. 791,809, allowed May 5, 1914, and my copending application for Letters-Patent, Serial No. 819,265, iiled Feb. 17, 1914, allowed June 5,1914.

One object of the present invention is to provide improved fluid pressure brake apparatus of this character including a lurality of brake operating pistons, a brakecylinder lin which they operate, and means to utilize a charge to move the pistons to brake applying position and one in advance of another.

Another object of the invention is to provide means for automatically locking the pistons together when in brake applying position and to automatically disconnect the pistons when they are moved to release position.l Another object of my invention is to provide improved fluid pressure brake apparatus of this character providing a plurality of brake operating pistons, a cylinder in which they operate and automatically operating means to utilize. a charge to move the pistons to brake applying position one in advance of another.

Another object of my yinvention. is to etfect improvements in the construction of the controlling valve carried by the main brake piston an which controls the operation of the prime acting" piston.

IAnother object of my invention is to provide improved compound air brake apparatus which may ordinary air brake apparatus.

Another object is to provide an improved compound air brake apparatus which operates automatically when pressure is reduced through the train pipe and which is at all times under direct control.v

Another object of my invention is to prov1de lmproved. compound iuid pressure brake apparatus the portions of which are cushioned by compressed iiuid when in ordinary brake applying position and prevented from locking the car wheels.

'Another object of my invention is to provide fluid pressure brake apparatus of this character Vwhich eii'ects a considerable econom of fluid under pressure in its operation.

nother object of my invention is to provide an improved compound air brake apparatus in which the controlling valve is actuated directly by air pressure and is prevented from sticking or getting out of order.

Another object of my invention is to provide improved compound air brake apparatus in which the pistons respond instantly to variations in air pressure so that the brakes are instantly applied when desired.

In the accompanying drawings Figure 1 is a vertical longitudinal sectional view of compound air brake apparatus constructed in accordance with my invention and in full release position.

Figure 2 is a detail sectional view, on a lar er scale, of the controlling valve.

igure 3 is a vertical longitudinal sectional Viewl on a scale larger than that of Figure 1`of the brake cylinder and pistons and showing the pistons in full release position.

Figure 4 is a similar view of the same with the brake pistons in running position.

Figure 5 is a similar view of the same with the pistons in brake applying position.

Figure 6 is a detail section showing the trip ring which operates the dogs.

Figure 7 is a detail sectional view showing the step by step mechanism for automatibe used in connection with cally adjusting the loralre loeam to compen= sate tor wear oi the hralre shoes Figure 3 is a vertical transverse sectional view on the plane indicated hy the line off-o oi? Figure l, n

Figure. 9 is a similar view on the plane indicated hy the line l--h ot lligure l.

Figure l is a diagrammatical plan ot the entire loralre mechanism.

ligure il is a detail plan ot the slaclr adiuster.

ln accordance with my invention the loralre cylinder l in which the main hralre operating piston 2 is mounted is connected to an auxiliary reservoir 3. A. pipe is here shown for connecting the auxiliary reservoir to the near end oi the cylinder, the pipe heing secured in a port in the rear head 5 ot the cylinder. A oypass pipe 6 also connects the auxiliary reservoir with the loralre cylinder, said pipe being attached to aeport i' in the wall ol the cylinder at a point near lout spaced from the rear head. rll`he train pipe S is shown connected directly to the outer or 'iront head 9 ot the loralre cylinder., a packing box l@ having a gland ll which is connected and Secured to the head 9 hy means ot bolts l2. A loralre lever is indicated at i3.

'lhe main 'brake piston 2 comprises a cylin-` der lll- 'ormed hy a cylindrical wall 15 having outstanding @anges l6l7 at its lfront and rear ends, a iront head F18 scoured loy bolts i9 to the Jfront end ot said l wall and a rear head 2() by' screws 21 to the rear end ot said wall. The piston 2 is oi somewhat less diameter than the bore of the loralre cylinder so that a slight space is termed between the ilanges of said piston and the wall ot the cylinder here. At the rear end ot the main brake piston is a paclru ing ring 22 which is secured between the rear end ot the wall l5 and the rear head 2() oy the screws 2l and this packing ring is provided with an expander 23. rlhe piston rod 2li ot the main brake piston. is tubular' and operates in the stuiing loon' and is provided at its outer end with an enlarged cylindrical head 25 which is here shown as open at its front end.

Cushioning and reacting springs 26 arranged in recesses 27 in the rear or inner head oi the brake cylinder l, project forwardly :from said .rear head and are adapted 'to'engage in resscs 28 ot the rear headA ot the main brake piston and to be com` pressed when the main brake piston is at the inner end of its stroke, in full release 'position, these springs being suiliciently strong to then torce the main brake piston 'forwardly a sufficient distance to cause its packing ring 22 to close the port 7.

'lhe main brake piston is provided on one side with an enlargement 30 through which extends a hote 3l. A passage 32 is also incesto made in the said enlargement yand extends JErom the trent ot the enlargement to the rear end,v ot the cylinder formed in said main loralre piston., A valve operating thrust har 33 is arranged tor longitudinal movement in the lloore 32 and in a here 3a ormled in the rear head 20 of the' main loralre piston, the rear end of said thrust har projecting trom the rear end ot the main loralre piston andvheing arranged in a stuhng loon 35 with which the head 20 is provided. A. cylindrical valve casing 36 is provided with an annular flange 37 and has its rear end 'secured in an opening 33 in the iront head 13 ot the main loralre piston hy holts 33. ln the rear portion ot the said valve casing, 'at one side thereof, is a passage d@ which communicates with; the passage 32 and also communicates with the interior ot said valve casing through a port ell. The trontend ot= the valve casing is 'formed 'hy a head l2 which has a central opening 43 that :terms also a seat i'or the conical head ot a checlr valve A screen l5 covers the iront tace of the head 4t2, entends across the opening t3 and is secured hy a ring 46 and bolts e7, which also secure the head l2 on the trent end oi the valve casing. A cylindrical controlling valve 48 o crates in the here oft the valve casing 36 and asastem 49 `which operates in the front portion ot the here 3l and engages the iront end ot the thrust har This controlling valve has a chamber 50 in its center9 open at its front end. and also has a port 5l which is formed by an annular channel around the valve and which communicates with thc chamber 50 at points indicated at 52. When the valve is at the iront end ot the valve casing its port 5i is out ot register with the port 41 and when said valve moves rearwardly in the valve casing its port 5l registers with the port l-l, as will he understood. The check valve tl has a stem 53 which operates in a bore 54 in the controlling valve. A light spring 55 is provided which closes the check valve in the opening 43 when pressure vis equalized on tooth sides of the check valve lout said spring is not sufficiently strong to prevent movelnient ot the check valve when there are variations 1n the pressure on opposite sides thereof.

The tubular rod 24C ot the main brake piston is provided near its outer end with openings 56 in which the trip arms 57 of dogs 58 are adapted to operate. The dogs are arranged in the. head 25, are pivotally mounted in the head as at 59. and are provided with heads 60 which are adapted to engage a shoulder 6]. in the rod 62 of a prime acting brake piston 63l which operates in the cylinder ll ot the main brake piston. lhe rod 62 has a reduced tapered portion 6tto term the shoulder 61. The piston rod 62 is of less diameter than and entends lil@ lll@

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fr 4 4l rescate through the bore of the tubular piston rod 24 and the outer end of the piston rod 62 is connected to the brake lever 13 as at 65. The prime acting brake piston 63 has a' packing ring 66 secured to its rear side by a ring 67 and screws 68. rlhe rear ends of the trip arms 57 of the dogs 58 are bevelled to rovide cam faces 69.

trip ring 70 is arranged a suitable distance in front of the stung box of the brake cylinder 1 andl is secured and held in place by means of bolts-71 which have nuts 72 which bear a ainst opposite sides of the said trip ring. hen the apparatus is in full Krelease position as shown in- Figure 3 the port 7 is open so that air pressure is equalized in the brake cylinder and in the auxiliary reservoir, the port 41 is open and the trip arms 57 are in and engaged by the trip ring 70 so that the dogs 58 are held in o en release oosition a ainst the tension of their` springs 73. Said springs are' secured at their inner ends in the head\25 as at 74, their free ends bearing on the outer sides of the dogs.

The brake pistons lstay in full release position only a short time, 4enough to equalize pressure in the brake cylinder and au'Xiliary reservoir, the cushioning springs 27 acting to move the main brake piston forwardly a slight distance, so as to cause its packing element 22 to close the port 7 land hence out. off communication through the bypass duct or pipe 6 between the brake cylinder 1 and the auxiliary reservoir.

To apply the brakes, tHe ports being-in the running position shown in Fi re 4, pressure is reduced inthe front end of the brake cylinder through the train pipe in the usual way. This causes pressure from the auxiliary reservoir throu h the port 4, to be eX- erted in the rear or inner end of the cylinder 1 and to move the main brake piston forwardly a suiiicient distance to cause the dogs, which move forwardly therewith, to be released from the trip ring 70. The con-P trolling valve tends to remain stationary owing to the pressure in the cylinder 1, but moves relatively to the main bra e piston so that its port 51`registers with the port 41, thereby establishing communication between the front end of the cylinder 1 and the rear portion of the cylinder 14 in the main brake piston, through the duct formed by the opening 43, chamber 50, port 51, port 41, and passages 40 and 3'2, as will be understood, the spring 55 yielding and permitting the check valve to open sufficiently for this purpose. Only a slight reduction of train pipe pressure is necessary but one that will give suiicient movement of the main brake piston to permit of a full opening of the controlling valve 33. After the main brake piston has moved this required slight distance the piston stops or slows and the smaller prime acting piston 63 moves forward more rapidly, applying the brakes at moderate pressure such as is ordinarily required to stop or control a train. The movement of the'rod 62 with the piston 63 causes the shoulder 61 of said rod to reach the heads of the dogs and thereupon the spring 73 enga e the dogswith such shoulder, thereby ocking the main brake piston and the prime acting brake piston together and if a further reduction of the pressure is effected, las lin an emergency. or where the entire power of the brake apparatus is desired both pistons move forwardly together and apply their ower to the brakes.

To release the rakes pressure is increased in the front end of the cylinder 1 in the usual Way and the pistons move rearwardly together until the cam faces 69 of the arms 57 of the dogs are engaged by the trip ring and the latter thus causes said arms 57 to be moved toward each other and the dogs to be opened and disengaged from theshoulder 61 of the rod of the prime acting brake piston. Thereafter the ypistons can complete their reverse movement independently of each other. The prime acting piston continues to move rearwardly with the main piston until the thrust bar 33 strikes the rear end of the brake cylinder 1 and causes the controlling valve to Amove forwardly, thus cutting ofi" communication between the ports 41 and 51 and opening ycommunication between the port 41 and the cylinder 14 of the main brake piston, thus relieving the pressure back of the prime acting piston 63 and causing the compressed air thus relieved to be exhausted into the air through `the duct 32, port 41, the front portion ofthe cylinder 14 and the bore of the tubular main brake piston rod 24 which also as before stated is of somewhat larger diameter than the rod 62 of the prime acting brake piston 63.

The spring 55 serves to close the check valve 44 when the pressure is approximately equal inthe main brake piston cylinder 14 and the brake cylinder 1. The said check valve when thus closed prevents pressure in the piston cylinder 14 from being reduced when a reduction of pressure is effected in the front end of the main brake cylinder. Hence the pressure in the piston cylinder 14 holds the piston 63 in 'forward position,

locked to the piston 2 by dogs and with cam portions 64 of the rod 62 pressing forwardly and tending to trip the dogs. This prevents the dogs from binding against the shoulder 61 and interfering with the brake release operation of the apparatus.

One especial advantage of the improved construction of my brake apparatus is that the valves are positively operated by the airl pressure so that they are prevented from sticking. Moreover the pistons respond indogs lock the two piston rods together and enable the pistons to operate as one when in service and-under more than usual pressure, andl enables them to move back to release position independently dot each other. lln

the event that there should be a'leakage al\ lowing air to leak frombehind the prime acting piston back into the Jliront end of the i brake cylinder, the dogs which serve to lock the two pistons together prevent V release movement of the prime acting piston, thus holding the brakes.

The main brake lever 7 5 has a travelling nut 76 connected thereto, this travelling nut being engaged by an adjusting screw shaft 77 which is mounted in bearings in a suitable support 73 at the rear end of lthe brake cylinder. A. ratchet wheel 79 which has relatively ine or narrow ratchet teeth is secured on said screw shaft to turn therewith. A bell crank lever 80 is suitably mountedrasat 8l and has a short arm which carries a dog 82 which is adapted to engage the ratchet wheel. `An arm 83 is secured as at 811- to the rod 62 of the prime acting brake `piston 63 and this arm 83 is connected by a link rod 35 to the longer arm of the bell crank lever 80, being pivotally connected as at 86-87 to said arm 83 and said long arm of the bell crank lever. 'llhe adjusting screw shaft is turned by a step by step movement and operated by the bell crank lever. @n each maximum servicemovement or the prime acting brake piston the ratchet wheel is turned a distance equal to the width or the space bei tween two of its teeth, thus slightly turning thev screw shaft and'hence correspondingly moving the travelling nut and causing the latter to `minutely adjustl the main brake lever and cause the latter to take up the slack occasioned by the wearing away of thed ton, a duct leadlng from sald port to the brake shoes. The ports are so proportione as to cause the main brake lever to be adliusted the required distance at each maximum operation of the brakes to compensate for the resulting wear of the brake shoes. rience the brakes automatically adjust themselves and are at all times kept in condition tor instant opeigation and lost motion is prevented. A

My improved compound air brake apparatus is adapted for use on elevators and the like as well as on railway trains.

Having thus described my invention, ll claim e l. ln tluid pressure brake apparatus ot the class described, the combination ot a brake er rasees@ cylinder, a main brake Liston in the brake cylinder and having a cy inder movable with said piston, a prime acting brake piston in the cylinder of the main brake piston, a :Huid pressure operated controlling valve carried y the main brake piston to charge the cylinder of the vmain brake piston from the brake cylinder on an initial braking movement of the main brake cylinderand cause the prime acting piston to move in said main piston, and means actuated by release movement orp the main piston to cause said valve to relieve pressure in the cylinder ont the main ,piston behind the prime acting piston, said valve operating means including a thrust rod carried by the main piston.

2.A lin iuid pressure brake apparatus of the.

class described, the combination of a brake cylinder, a main 'brake piston inthe brake cylinder and having a cylinder movable with said piston, said piston cylinder being provided with a valve casing communicating with the front end of said piston cylinder also havino" a port, and said piston cylinder having a duct leading from said port to the rear end of said piston cylinder, a prime acting brake piston lin the cylinder of the main brake piston, a valve in the casing, movable by duid pressure on an initial braking movement of the main piston to cut oft communication between the ends olf said piston cylinder and establish communication between the brake cylinder and the rear end of said piston cylinder and thereby cause the prime acting piston to be moved to brak- -ing position, and means operated by release movement of tw main brake piston to cause said valve to cut oii" communication between the brake cylinder and the cylinder of the main brake vpiston and to also relieve pressure in the cylinder of the main brake piston behind the prime acting piston.

3. lin Huid pressure brake apparatusof the class described, the combination of a brake cylinder, a main brake piston in the brake cylinder and having a cylinder movable with said piston', said piston cylinder beingV provided with a valve casing communicating with the front end of said pisrear end of said piston cylinder, a prime acting brake iston in the cylinder of the main brake plston, a valve in the casing, movable by fluid pressure on an initial braking movement of the main piston to cut ed communication' between the brake cylinder and the rear end of said pistonv cylinder and thereby cause the prime acting piston to be `moved to braking position, and means operated by release movement of the main brake piston to cause said valve to cut ont communication between the brake cylinder and the cylinder of the main brake piston and t0 also relieve pressure in the cylinder of the main brake piston behind the prime acting Mld lll@

piston and a check valve carried by said controlling valve to close against back pressure When said valve is in the re uired position to charge the cylinder oil the main brake piston.

4. In fluid pressure brake apparatus of the class described the combination of a brake cylinder having an intermediate port and a duct' connecting said port to the rear end of said cylinder, a main brake piston to vopen said port When in full release position,

means to move said piston to running position and cause the same to close said ort, a cylinder carried by said piston and avin a duct leading from the rear end of said cy inder to the interior of the brale cylinder, a valve to control said duct and thereby charge and relieve said piston cylinder and a prime acting brake piston arranged to operate in the cylinder of said main brake piston.

5. In fluid pressure brake apparatus of the class described the combination of a brake cylinder having an intermediate port and a duct connecting said port 'with the rear end of said cylinder, a main brake pist0n to open said port when in full' release position, means to move said piston to running position and cause the same. to close said port, a cylinder carried by said main.

' brake piston and having a duct leading to the rear end of said cylinder, a valve casing carried by said piston cylinder and having a port communicating with the interior of the brake cylinder, a relief port for the piston cylinder and a port forming one end of said cylinder duct, a valve in said casing, actuated by saidvbrake cylinder pressure to close the' relief port and openithe charging port ofthe cylinder of the main brake piston on an initial? movement of said piston, a prime acting brake piston arranged to operate in the cylinder of the main brake piston and means operative on release movement of the main brake piston to cause said controlling valve to relieve pressure in the cylinder of the main brake piston behind the prime actin brake piston.

6. n fluid pressure brake apparatusof the class described the combination of a brake cylinder having an intermediate port and a duct connecting said port to the rear end of said cylinder, a mam brake piston to open said portwhen in full release position, counter-acting cushioning means to move said piston to running position and cause the same to close said port, a cylinder carried by said piston and having a duct leading from the rear end of said cylinder to the interior of the brake cylinder, a valve to control said duct and thereby charge and relieve said piston cylinder and a prime acting piston arranged to operate in the cyl-v inder of said main brake piston.

7. In fluid pressure brake apparatus of the class described, the combination of a brake cylinder, a main brake piston in the brake cylinder having a cylinder movable With said piston and also having a tubular piston rod; a prime acting brake iston in the cylinder of the main piston, piston rod operative in the tubular rod of the main cylinder, means operative on an initial movement of -the main piston to charge the cylinder thereof and cause the prime acting piston to move therein, means to lock the piston rods of said pistons together after an initial braking movement of the prime acting piston, and means actuated by release movement of the main piston to cause said charging means to relieve pressure inthe cylinder of the main piston behind the prime acting piston.

8. In fluid pressure brake apparatus of the class described, the combination of a brake cylinder, a main brake piston in the brake cylinder having a cylinder movable with sa1d piston and also having a tubular piston rod; a prime acting brake piston in the cylinder of the main piston, having a piston rod operative in the ytubular rod of the main cylinder, means operative on an initial movement vof the main piston to charge the cylinder thereof and cause the prime acting piston to move therein, means to lock the piston rods of said pistons together after an initial braking movement of the'prime acting piston, means actuated by release movement of the main piston to cause said charging means to relieve pressure in the cylinder of the main piston behind'the prime acting piston, and means to disconnect said pistons during brake release movement.

In testimony whereof, I aiiix my signature.

WILLIAM GCANION.

aving a f 

